The white residue or spots on your glassware are typically caused by minerals like calcium and magnesium found naturally in water. These minerals are common in what’s known as “hard” water. However, they don’t pose any health risks; in fact, they can contribute to your daily intake of calcium and magnesium, which are important nutrients according to the National Research Council. Many people even prefer the taste and health benefits of water with these minerals over distilled or “soft” water.
To remove these mineral deposits from your cookware, you can boil a mixture of equal parts white vinegar and water. Similarly, to clean your coffee maker, fill the reservoir with the same vinegar-water mixture and run a cycle.